Machine for manufacturing toothed wheels, screw wheels, or the like



July 31, 1923. 1,463,414

S. G. WINGQUIST MACHINE FOR MANUFACTURING TOOTHED WHEELS, SCREW WHEELS, OR THE LIKE Filed March 1921 4 Sheets-Sheet 1 July 31, 1923.

- S. G. WINGQUIST MACHINE FOR MANUFACTURING TOOTHED WHEELS, SCREW WHEELS, OR THE LIKE Filed' March 2, 1921 4 Sheets-Sheet 2 mvavrmz.

July 31, 1923. 1,463,434

- s. G. WINGQUIST MACHINE FOR MANUFACTURING TOOTHED WHEELS, SCREW WHEELS, QR. THE LIKE Filed March 1921 I v 4 Sheets-Sheet 5 //v VENTOR.

July 3 1, 19123; I 1,463,414

S. G. WINGQUIST MACHINE FOR MANUFACTURING TOOTHED WHEELS, SCREW WHEELS, OR THE LIKE Filed March 2, 1921 4 Sheets-Sheet 4 lid SW1 GUSTAF PW-1*.

svms S.

BEA i:

Application filed march 2, 1921.

To all whom it may concern:

Be it known that I, Sven Gnsrar WING- Qms'r, a subject of the King ofSweden, residing at Gottenborg, in the Kingdom of Sweden, have invented new and useful improvements in Machines for Manufacturing Toothed Wheels, Screw eels, or the like, of which the following is a specification.

This invention relates to machines for manufacturing toothed wheels, worm wheels or the like according to the rolling principle or according to any other principle in which the relative rolling movement of the cuttin tool with respect to the wheel blank is e fected by means of a system of suitably arranged links. An indispensable requirevment which must be satisfied in order that such motion transmitting devices shall give a practically suliicient result as to the toothprofile generated, involves that the angles of the rolling movement are given comparatively small values, as in the case of ater angles of rolling the movement controlled by the link system will not be a pure rolling movement, but a combined sliding and rolling movement. in machines as heretofore known, having a link system for controlling the relative rolling movement of the wheel blank with respect to the cutting tool, the said movement has taken place between a position representing the normal or zero position of the link system, and an end position corresponding to the necessary angle of rolling. in each case. The machines are, in other words, so constructed that the whole rolling movement will take place at one and the same side of the normal position of the link s stem, and as a result the tool has been placed in the point where the rolling movement begins as determined by the link system. By such an arrangement of the link system as well as of the cutting tool, however, it was not ossible to keep the angle of roll within to limits giving practical results and, owing to this, machines havin link motions of the kind above describe, have not been practical. This invention has for its object to enable the use of comparatively large angles of rolling without causing the irregularit to exceed the practically a1 owed limit. 1 is result is obtained according to this invention by placing the cut- UIST, 0E GOTTENBOBG, emrnm, 0E GO'ET 1 FOE UFACEUEENG TOOTHED scnnw r on ran an.

serial No. M83207. I

distance between the two end positions of the link sysmm, and the rolling movement may, preferably, take place symmetrically at both sides of the normal position of the link system. i

The invention is illustrated in the accompanying drawings. matic view of a well-known link system. Fig. 2 illustrates in a dial" ammatic maer an arrangement of the li: system according to this invention. Fig. 3 illustrates diagrammatically the use of the known link system in a machine for manufacturing spur gear wheels. Fig. 4 illustrates in a diagrammatic manner the use of the link system in a machine according to this invention. Fig. 5 shows difierent tooth-profiles. Fig. fishows a modified arrangement of the link system according to this invention. Fig. 7 is a top plan view of a machine having incorporated therein a link system'according to Fig. d. Fig. 8 is a side elevation of the machine of Fig. 7 partly in section.

The well-known link system shown in Fig. 1 by means of which the cylinder C is given a rolling movement on the surface P, comprises two links a and h, of which the link a is rigidly connected to the axis as of the cylinder 0 and has a length corresponding to the radius of tlie cylinder, while the link. I) which is pivotally and slidably connected to the link a at a, is provided with an axis a, stationary with respect to the axis at the said link h being Fig. 1 is a diaamfurther pivotally and slidably guided at the hilt scribed part of a cycloid Z. it is now readily understood that such anideal roll- 7 ing movement cannot be obtained by means the movementof the cylin er C under the of rolling iii control of the link system a, b from the initial position 0 and into the osition 0. As shown, the curves Z and K Wlll coincide at and in the proximity of the initial point 0 while diverging from each other according as the angle of rolling V increases, In order that the link system shbwn in Fig. 1 may give practical results, the angle of rolling V, therefore, should be very small, or, in other words, it is necssary to l1m1t the movement to a fairly small part of the curve K at and in the neighbourhood of the initial oint 0, where the curve K coincides fu 1y or approximately with the ideal cycloid Z thereby making the irregularity exceedingly small at this point. As, however, comparatively large angles of rolling and in any case, angles larger than those obtainable by means of the link system a, b, will. be used in practice, it is understood, that the link systemshown has no practical importance. llhe present invention permits of limiting the movement to the comparatively small part of the curve K above referred to while maintainin the comparatively large angle W shown in Fig. 1. It is evident that by, said arrangement, a great advanta e may be gained. This is obtained accor ing to this invention by causing the rolling movement to take place at both sides of the normal position of the link system and referably, as shown in Fig. 2, symmetrically with respect to said position so that the angles of rolling V at either side of the neutral position will be equal to each other and each equal to half the angle V, Fig. 1. The total angle of rolling between the end positions o,,o of the cylinder C will, as is readily understood, be efglal to the angle V, Fig. 1, the movement, owever, having been limited as seen from the middleposition 0, to those parts of the acute curve K which practically coincide with the cycloid Z, that is, the movement of the cylinder C with respect to the surface 1? from the position 0 and into the position 0 corres 0ndto the movement from the position 0 into the position 0 in Fig." 1, will become a practically ideal rolling movement.

In the link systems shown 1n Figs. 1 and 2 the initial point 0 isasumed to be stationary d the rollingof the cylinder 6 on the plane surface P is accomplished by displacneonate ing the axes of rotation :12 and m, with equal cally shown in Fig. 3, for manufacturing cylindrical toothed wheels the axis of rotation at of the wheel blank H as well as the axis of rotation :0 of the link 6 are assumed to be stationary, while the guiding point 0 of the link I) may be displaced along the imagined plane surface 1?. Placed in the point 0 is a tool W of any appropriate kind, as for instance, a cutting too a grinding disc or the like, moving with the point 0. Assuming now that the wheel blank H is caused to rotate about its own axis a; and that the tool W is displaced along the-surface P representing the tangent to the circle of rolling C, with a speed c ual to the circumferential s eed of the circ e of rolling C, it is evident t at the tool W will describe an ideal involute. If, on the other hand,

the relative movement between the wheel blank H and the tool W be performed under the control of the link system a, b, the tool W will form a tooth-profile E which, as

stated in connection with the description of indicates the ideal invo ute, E is the tooth-' profile which may be obtained with the known link system, and E is the toothprofile according to this invention. The deviations of the rofiles E, and E from the ideal involute%l for the sake of clearness are shown as having an abnormal value. From this figure it w1ll be seen that the profile E is much more favourable than the profile E the unavoidable error being not only considerabl reduced as compared with that of the profi e E but also distributed towards the top and root of the tooth, so that the error at or near the middle section of the tooth will be zero. B suitable variation of the extension of t e rolling movement at both sides of thenormal position of the link system and by a correspong tense of the Petit on 9f the tool it is pos' to an I are sible to have the errorplaced at the top or at the root of the tooth at will, so that the profile at the top or at the root of the tooth will, practically, coincide with the ideal 1nvolute.

In the embodiment shown in Fig. 4: the tool W is assumed to move from an end position into another end position coincidlng with the normal position of the link system. However, this is not necessary as the relative position of the tool with respect to the link system may, as stated, be chosen at will.

In Fig. 6 there is shown an embodiment of the invention in which the tool W is always situated at the side of the normal osition of the link system. The distance tween the tool W and the oint where the rolling movement begins wil in this case be equal to the distance between the normal position of the link system and the pitch-circ e G, of the wheel blank as seen along the tangent to the rolling or base circle of the wheel blank along which the tool W is assumed to move. The tool W will, thus, intersect with the pitch circle G, of the wheel blank at the same time that the link system is 111 1ts normal position, thereby securing the essential advantage that the error will become zero 'ust at the pitch circle where, as is wellnown, pure rolling'movement takes place between two cooperating teeth. At other portions of the tooth-profile there will also take place a sliding movement to a certain degree so that in the case of an error at those parts of the profile, wear to compensatefor said error may more easily occur in work ng. The rolling movement will in this case be non-symmetrical with respect to the normal position of the link system.

The invention is especially applicable to such machines for manufacturing toothed wheels and the like, in which, as is shown in Figs. 4: and 6, the tooth-profile is generated by means of one and the same point, line or small surface of the tool which assumes a constant position with respect to the system of the tool and which is caused to move along the line of contact. The necessary angle of rolling will in this case be less than in machines working on the so called rolling princi 1e.

In igs. 7 and 8 there is shown a constructional form of the link system according to Fig. 4 incorporated in a machine. In these figures, 1 designates a frame carrying a slide 2 movable in the direction of rolling and forming a bearing for the shaft :12 of the link a as well as for the shaft a" of the link I). The link 6 is provided at one end with a pivot O mounted in a bearing 3 formed in the frame 1, and a seat or guideway 4 is formed in the link at the same end to receive a slide 5 carrying the ivot a of the link or crank a which latter is connected at its opposite end to the shaft :0. At its outer end, link 6 has formed in it a guideway or seat 6 to'receive a slide 7 which carries the shaft at, so that upon the displacement of the slide 2, and the resulting swinging movement of the link I) about the fixed pivot O, the shaft m with the slide 7 maly be displaced relatively to the link I).

' igidly connected to the shaft w of link a is a table 8 to receive the wheel blank H to be rolled relativel to the tool by means of the link system. he tool in the present instance is in the form of a rotary grinding wheel W carried by a shaft W mounted in hearings in the frame 1 and provided with a pulley W for rotating it.

The operation of the device corresponds in ;all essential particulars to that described in connection with Fig. 4 andbriefly stated is as follows: The wheel blank having been clamped to the table 8, and the grinding wheel W having been adjumed corresponding'to the itch circle of the wheel blank, the wheel 18 rotated and the slide 2 at the same time displaced slowly in its guides, which action will bring about a relative horizontal movement of the wheel blank with respect to the tool at both sides of the normal position of the link system, whereby a complete tooth space will be formed in the wheel blank.

lit should be understood that the invention is not limited to the embodiment of the link system shown in the drawing, as it may be applied to any link system for controlling .rollin movement. The invention may further e applied not only. to machines for manufacturing spur gear wheels but also to machines for manufacturing bevel gear wheels, screw wheels or the like.

What I claim is 1. In a machine for manufacturing gear wheels according to the principle set forth, the combination with a tool of a link system to cause a relative rolling movement between the tool and a wheel blank to take place at both sides of the normal position of the link Mill lid

system, the tool being placed at a distance from the starting point for the rolling movement as determined by the link system.

2; In a machine for manufacturing gear wheels according to the principle set forth, the combination with a tool, of a link system to cause a relative rolling movement between the tool and a wheel blank to take place symmetrically at both sides of the normal position of the link system, the tool being situated at a distance from the starting point for the rolling movement as determined by the link system which is equal to half the dis tance between the end positions of the link system.

3. In a machine for manufacturing gear wheels according to the principle set forth, the'combination with a tool, of a link system to cause a relative rolling movement between the tool and a wheel blank, the movement of the tool relativel to the Wheel blank taking place within limits situated at theside of the normal position of the link system. v Y a 4. In a machine for manufacturing gear wheels according to the principle set forth,

, the combination with a tool, of a link system to cause a relative rolling movement between the tool and a Wheel blank to take place at both sides of the normal position of the link system, the tool being situated at a distance from the starting point for the rolling movement as determined by the link system, which is equal to the distance from the nor mal position of the link system to the pitch circle of the wheel blank, as measured on the tangent of the wheel blank, along which the rolling movement may be assumed to take place. I a

5. In a machine for manufacturing gear wheels according to the principle set forth, the combination with a tool, of a link system to cause a relative rolling movement between the tool and the wheel blank to take place at both sides of the normal position of the link system, the tool being so arranged as to form the tooth-profile by causing one and the same point, line or small surface of the tool, having a constant position thereon, to move along the line of contact of the tooth-profile,

In testimony whereof l have signed my name.

SVEN GUSTAF WINGQUIST. 

